title: All-polymer solar cells with 3.3% efficiency based on naphthalene diimide-selenophene copolymer acceptor.
abstract: The lack of suitable acceptor (n-type) polymers has limited the photocurrent and efficiency of polymer/polymer bulk heterojunction (BHJ) solar cells. Here, we report an evaluation of three naphthalene diimide (NDI) copolymers as electron acceptors in BHJ solar cells which finds that all-polymer solar cells based on an NDI-selenophene copolymer (PNDIS-HD) acceptor and a thiazolothiazole copolymer (PSEHTT) donor exhibit a record 3.3% power conversion efficiency. The observed short circuit current density of 7.78 mA/cm(2) and external quantum efficiency of 47% are also the best such photovoltaic parameters seen in all-polymer solar cells so far. This efficiency is comparable to the performance of similarly evaluated [6,6]-Phenyl-C61-butyric acid methyl ester (PC60BM)/PSEHTT devices. The lamellar crystalline morphology of PNDIS-HD, leading to balanced electron and hole transport in the polymer/polymer blend solar cells accounts for its good photovoltaic properties.
authors.affiliation: Department of Chemical Engineering and Department of Chemistry, University of Washington , Seattle, Washington 98195-1750, United States.
authors.forename: Taeshik
authors.initials: T
authors.lastname: Earmme
authors.forename: Ye-Jin
authors.initials: YJ
authors.lastname: Hwang
authors.forename: Nishit M
authors.initials: NM
authors.lastname: Murari
authors.forename: Selvam
authors.initials: S
authors.lastname: Subramaniyan
authors.forename: Samson A
authors.initials: SA
authors.lastname: Jenekhe